Modern lubricant compositions are widely used in various applications such as motor oils, transmission fluids, gear oils, power steering fluids, shock absorber fluids, brake fluids, hydraulic fluids and greases. The lubricant compositions can have various functions such as (1) controlling friction between surfaces of moving parts; (2) reducing wear of moving parts; (3) reducing corrosion of surfaces of moving parts, particularly metal surfaces; (4) damping mechanical shock in gears; and (5) forming a seal on the walls of engine cylinders. Each lubricant composition can contain a base oil and, depending on the application, a combination of additives or modifiers, such as viscosity index improvers, pour point depressants, dispersants, detergents, anti-wear agents, antioxidants, friction modifiers, rust inhibitors, corrosion inhibitors, demulsifiers and anti-foams.
The base oil in various lubricants are formulated from a range of natural or synthetic oils or polymers or various combinations thereof. The base oil has several functions; but primarily it is the lubricant, providing a fluid layer separating moving surfaces or removing heat and wear particles while keeping friction at a minimum. The base oil also functions as a carrier for various additives that enhance the properties of the lubricant. The base oil, therefore, is required to keep the additives in solution under all normal working conditions.
Poly-α-olefins (“PAOs”) are synthetic hydrocarbons which are widely used as lubricant base oils. Various properties of PAOs make them suitable for use as lubricant base oils in engine oils, compressor oils, hydraulic oils, gear oils, and greases. However, PAOs that have been characterized to date have limited oxidative stability and limited biodegradability. The cost of producing PAOs is relative high. Therefore, it is desirable to manufacture a lubricant base oil that is more cost-effective and has improved in use life-time than the current base oils for lubricants.